grip dynamic analysis

[leonj]

hello there

I am currently using inventor 2012 student edition
I am trying to run a dynamic simulation to get true forces out of a grip assembly I have designed.
Its is for the tensile testing of rubber which I have modelled the test piece.
The gripping motion is driven pneumatically, for this I have applied a force to the end of the shaft where the air pressure would be applied.
The body is one solid aluminium part with a U shape cut in to the middle where the test piece sits on the left wall and the plate (attached to the piston) comes in from the right to apply pressure.
Once closed that test piece then has a force applied to it to draw it upward.
I have applied 3d contact constraints to the test piece and made it adaptive.
My problem is that the simulation does not start, it has been running for 2 hours now with out any sign of moving.
If I do not apply the frictional forces. The test piece is squeezed out and is then a test of the piston against the wall of the body.
I have attached a screen shot of the current problem

Many thanks in advance

 

[rollupswx]

I am not familiar with editing screen shots in Inventor.
Attatch your assembly here.